Generation IV Internal Engine - Motor shot?

Hey guys,

So I have a 98 Camaro with LS1 and 6 speed. I drove it to work Monday and it drove completely fine with no prob. Let the car set for two days due to me leaving town. when I cranked it yesterday it sounds like something is broking inside the motor and is knocking and rattling.

I have know clue what has happened here any ideas. ... the motor is also now leaking oil out the back

Oil filter leaking and all oil ran out? How is oil level?

or rear main,, or the oil sending unit, and is it a lifter noise

the oil level was fine and it did not start leaking till after I started it and it had the knock... sounds like it is in the bottom of the motor